Apparatus for burning powdered coal.



A. J. GRINDLE.

APPARATUS FOR BURNING FOWDERED COAL.

APPUCATION FILED JULY 7.1916.

1,81 5,71 9. PutentedSept. 9, 1919.

3 SHEETS--SHEET I.

Kw h g e/ jn z iie A. J. GRINDLE.

APPARATUS FOR BURNING POWDERED COAL.

APPLICATION FILED JULY 7,1916.

Putentedsept. 9, 1919.

H f v 4 5 s 5 7 -?llllllfifa In I. I. I O O o O O O O O O O O O O O O Patented Sept. 9, 1919.

3 SHEETS-SHEET 3.

A. J. GRINDLE.

APPARATUS FOR BURNING POWDERED COAL.

APPLICATION FILED JULY 711915. 1,315,719.

UNITED STATES PATENT OFFICE.

AUBREY J. GBINDLE, O1 CHICAGO, ILLINOIS, ASSIGNOB 'IO COMBUSTION IlCONOIY COMOBATION, OF CHICAGO, ILLINOIS, A CORPORATION.

Specification of Letters Patent.

Patented Sept. 9, 1919.

Application filed July 7, 1910. lei-ll! No. 107,800.

To all whom it may concern Be it known that I. AUBREY J. GRINDLE, a citizen of the United States, and resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Apparatus for Burning Powdered Coal, of wlnch the following is a specification, and which are illustrated in the accompanying drawings, forming a part thereof.

The invention relates to apparatus for the use of powdered coal as fuel and has especial reference to the provision of improved means for obtaining a uniform, regulated delivery of the fuel, a uniform admixture of the fuel with the amount of air required for combustion and an effective delivery of the mixed air and fuel into the furnace. The object of the invention is to provide an 0thcicnt and economical apparatus of the kind described.

In the accompanying drawings,

Figure 1 is a general side view of apparatus embodying the features of improvement provided by the invention, some of the parts being shown in central section,

Fig. '2 is an enlarged detail plan sectional view taken on the line 22 of Fig. 1,

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2,

Fig. 4 is a detail longitudinal sectional view showin the parts illustrated in side elevation in Fig. 1, drawn to a larger scale,

Figs. 5 and 6 are sectional views both taken on the plane indicated by line 5-5 on Fig. 4, but showing the parts as viewed in opposite directions at said plane.

*ig. 7 is an enlarged detail side elevation partly in section showin a form of burner which is preferably emp oyed for introducing the mixed air and fuel intothe combustion chamber of a furnace,

Fig. 8 is a detail plan view partly in section, the plane of the section beln indicated by the line 88 on Fig. 7, and i 9 is a detail sectional view taken on the hue 9-9 of Fig. 1.

The powdered fuel is preferably supplied from a hopper, as 10. This hopper is desirably constructed with a trough shaped bottom section 11 having a delivery tube 12 at one end, and a feed screw 13 is located" in the hopper section 11 and preferably extends entirely through the same to the outer end of the said delivery tube. In the construction shown, the feed screw 13 is provided with multi le threads 14, and each of these three s is formed with an abrupt forward face 15 and a sloping rearward face 16. While each of the threads 14 extends continuously from end to end of the feed screw 13, the removal of the material from the hopper 10 will proceed more uniformly throughout the length of the hop er, if the threads 14 are of increasin dept as they approach the discharge tiil) conveniently accomplished while still maintaining the same external diameter throughout the length of the feed screw if the threads 14 are formed about a tapering core 17. As shown, the threads 14 and core 17 are cast integral, the latter being tubular to permit of the feed screw 13 being sleeved over a shaft 20.

The shaft 20 is extended through the wall ofthe hopper section 11 at one end for the application of power thereto for driving th feed screw 13. For this urpose, a sprocket wheel 21 may be mountet upon the projecting end of the shaft. The other end of the shaft 20 extends beyond the end of the discharge tube 12 and crosses the chamber of a housing 22which is-applied to and covers the end of the discharge tube. As shown, the housing 22 has tapering sides and is extended below the discharge tube 12 for the connection therewith of the carrying air supply pipe 23 anda conveying tube 24. Preferably the lower end portion of the housin 22 is constructed to receive a contracte nozzle 25 for the carrying air supply pipe 23. This nozzle faces the inlet end of the conveying tube 24 and the air jet issuing therefrom serves to induce the flow of material from the chamber of the housing 22 into the conveying tube.

A cooperating fixed plate 26 and rotatable plate 27 serve for regulating the discharge of fuel by the feed screw 13 into the chamber of the housing 22. These plates are preferably constructed. with coacting ribbed faces 28 and 29. As shown, the plate 26 has a central opening 26 of substantially the same size as the outside diameter of the feed screw 13 and this plate is secured against the wall of the housing 22 upon the inside of the same in front of the said feed screw. The plate 27 is made in the format-=- a disk and is splined upon the shaft 20 to rotate therewith at a regulated distance 85 e 12. This is Iii from the plate 26. The opening between the plates 26-and 27 is adjustably varied by slidlng the disk 27 upon the shaft 20. For this purpose a collar 30 having a plurality of radial arms 31 is fixedu ontheshaft 20 adjacent the hub of the p ate 27 and adjusting bolts 32 are extended through the plate'27 and into the arms 31 of the collar. The housing 22 has a removable cover late 22 to rovide access to the adjusting olts 32.. I desired this cover plate may be removed during the operation of the device,

in which case a current of air will be induced to flow downward] through the chamber of the housing 22 by the jet issuin from the nozzle 25.

lhe conveying tube 24: will usually enter the volume air sup ly pipe, as 33-, a short distance from the urnace, indicated at 34, as at an elbow 35. Under these circumstances any precipitation of the fuel in the pipe 33, beyond the elbow 35, is effectually prevented and a uniform admixture of the volume air with the fuel is insured if sta- 25 tionary inclined blades 36 are located in the pi e 33 at intervals between the elbow 35 an thefurnace- As shown, the inclined blades 36 are arranged in pairs of sets 37, 38, the blades in he two sets of each pair being 30- oppositely inclined and three such pairs of sets being employed. By locating the oppositely inclined sets 37 and 38 of each pair adjacent the axis and the periphery of the pipe 33, respectively, and by oppositely Slimli'lfilllllllg corresponding sets of adjacent pairs, the matter traveling through the axial and peripheral portions of the pipe 33 willbe oppositely whirled in reverse directions in rapid succession. to are provided the portion of pipe 33 adjacent the burner may be regarded as a mining chamber and will be so referred to in- I some of the claims. However, notwithstanding the presence of themixing" blades, to the portion of the pipe 33 where they are located while serving as a mixing chamber is none the less a conveying tube.

The burner, as 39, is preferably constructed with a flaring mouth piece 40 of so oblong rectangular shape and with a tubular shank 41 which vanes in shapethrough out its length to fit the pipe 33 at one end and to connect with the smaller end of the mouth piece {10 at the other end. The mouth piece 40 of the burner 39 enters -a correspondingly shaped o ening 42 in one of the walls, as 4.3 of the urnace 34. While the mouth piece 40 of the burner and the opening 42 in the furnacewall are shown as lie-- ing of increasing size toward the furnace chamber, the discharge of air and fuel from the burner is preferablyconfined to a flat stream which is of reduced thickness, as

compared with the diameter of the pipe 33. This may be accomplished by-the-use of a W hen the blades 35' pair of swingin deflector plates 44, 45. As shown, each de ector plate 44-, 45, is fixed upon a spindle 46 which extends through the side wall of the burner 39', at oneend and is there rovided with a crank arm 47 for turning the spindle to adjustably p0sition the corresponding plate. To provide a convenientmeans for securin the deflector plates 44, 45 in angularly a justed positions, each crank arm 47 is formed wlth a curvedslot 48 and a .set screw- 49 passes through this slot and enters a bracket lug 50 formed upon an adjacent part of the wall of the burner 39.

In some instances it will be desirable that so parts of the walls of the burner 39 and the deflector lates 4:4, 45, should be water cooled. is is readily accomplished with respect to the walls of the burner 39 by makin the corresponding parts of these walls hollow, as indicated at 51, and providing them with Water inlet and outlet nipples, as 52, 53. The deflector plates 44 and d5, on the other hand, may be supplied with 7 water through the spindles 46. As shown, to each s indle 46 is made tubular for a portion oi: its length adjacent each end, as indicated at 54, 55, and water supply and discharge pipes 56, 57, are connected with the two spindles at one end. A union 57, have5 ing a swiveled connection 58 with each spinolle 46 serves to connect the two spindles at the other end. The deflector plates ld and 4.5 are made hollow and their chambers, as 59, are constructed with bafies 60 and 31 to insure the circulation of water to that part of the chamberwhich is adjacent the outer end of the plate. chamber 59 communicates with the bores oi the tubular end portions 54, 55 of the corresponding spin- 305 die 46, through port openings 32 and 63. This construction permits of the angular adjustment of the deflector plates dd, 45 without interfering with the circulation of water through the same. it will be observed that both the depth and direction of the flame may be modified by the angular adjustment of the two deflector plates.

It the furnace 34: is to be used as a melting furnace, a part, as 61 of the furnace chamber adjacent the wall 43 serves as a combustion chamber and is preferably provided with an inclined floor 52 which slopes to ward the hearth 63 The slag or melted ash which results from the combustion of the powdered coal thus drains onto the bath of molten metal and mingles with the slag which usually floats upon such a bath. To provide suitable 'bafies for the flame to impinge upon for maintaining the ignition, especially during the early part of the melting operatlon when cold metal is piled upon the hearth 63, a row of masonry piers 64 extending from side to side of the combustion Jill chamber with openings 65 between the piers may be erected upon the floor 62' adjacent the hearth 63". By reason of the openings burner 39 is shown'for simplicity of illus-- tration it will be understood that as many burners will be employed as may be necessary to cover the'furnaoe from side to side and that a separate fuel feeding apparatus may be employed for each burner.

A supplemental air suppl introduced in a flat stream, as through a s otted opening 66 in the to of the furnace may be employed for epressin the flame over the hearth. Preferably t e opening 66 takes the form of a continuous slot extending from side to side of the furnace. When air under pressure is introduced through the opening 66 the volume air introduced through the pipe 33 may be reduced in amount. While the depression of the flame by the introduction of a Hat stream of air through the opening 66 serves to sweep the slag along the bath toward the remote end of the furnace, the oxidation of the bath may be effectively controlled by a suitable proportioning of the total amount of air employed to the amount of fuel.

To permit of the nozzle 25 being adjusted 7 toward and away from the inlet end of the conveyin tube 24, it may be slidingly entered in t he corresponding side wall of the housing 22. As shown the outer end of the nozzle 25 is formed with an outstanding annular flange 67 and adjusting screws 68 are extended through this flange and into the adjacent side wall of the housing 22 for adjustably positioning the nozzle 25. The gatherin up of the powdered coal as it falls into the fiiwer part of the housing 22, by the current of air enteringthe conveying tube 24, is facilitated if an annular series of port openings 69 are provided in the side wall of the housing 22, about the nozzle 25. Air is thus drawn into the chamber of the housing 22, through the port openings 69 and mingles' with the air which is supplied through the pipe 23, as it enters t tube 24.

When the furnace is largely filled with cold iron, ignition is more readily maintained if the deflector plates 44, 45 are adjusted to cause the flame to play upon the floor 62 of the combustion chamber 61". Later on in the operation, the employment of the deflector plates 44, 45, is not essential and when these plates are present, as shown, they will preferably be so adjusted that e conveying 5 their free ends are separated the full distance permitted by the depth of the mouth piece 40.

I claim as my invent1on:--

1. In an apparatus for burning powdered fuel, in combination, a burner, a tubular mixing chamber delivering to the burner, volume and carrying air supply pipes delivcling to the said mixing chamber and two sets of inclined blades located within the mixing chamber, the blades of the two sets being oppositely inclined and the blades of one set being arranged in an annular series adjacent the wall of the mixing chamber and the blades of the other set being located within the space which is inclosed by the said annular series of blades whereby the two sets of blades act simultan ously but independently upon different parts of the air and fuel current passing through the mixing chamber, the said different parts of the air and fuel current being respectively 10- cated adjacent the axis of the mixing chamber and adjacent the wall of said chamber. 2. In an apparatus for burning powdered fuel, in combination, a burner, a tubular mixing chamber delivering to the burner, volume and carrying air supply pipes delivermg to the said mixing chamber, and a plurahty of pairs of sets of stationary inclined blades located at intervals in the length of the mixing chamber, the blades of the two sets of each pair belng oppositely inclined, the blades of one set of each air being an ranged in an annular series ad acent the wall of the mixing chamber, the blades of the other set of eachpair being located within the space which is inclosed by the annular series of blades of the same pair and the blades of the corresponding sets of adjacent pairs being oppositely inclined.

3. In an apparatus of the kind described, in combination, a hopper for powdered coal or the like having a discharge opening, a chambered housing covering the discharge 0 ening of the hopper and extending below t e same, a feed screw operating within the hopper to deliver to its said opening, the SElIldlG of the feed screw being extended t rough the hopper opening into the chamber of the said housing, a plate larger than the hopper opening mounted upon the feed screw spindle to rotate therewith within the chamber of the said housing, the face of the p ate cooperating with the face of the inside wall of the housing about the hopper opening to regulate the discharge of material through t e said opening into the chamber of the housing, a jetburner a conveying tube leading laterally out of the chamber of the housing at one side of the same below the ho per opening and plate to the burner,

all

in combination, a hopper for powderedicoal" or the like having a discharge opening, a

ber: of the said housing, a plate larger thanthc'hopper opening mounted upon thefeed screw spindle to rotate therewith within the chamberof the said housing, the'face of the plate'coperating' with" the face of the inside wall of the housing about the hopper opening to regulate the discharge of ma terial through the said opening-into the chamber of thehousing, a jet burner, a tubular mixingchamber delivering to the burner, a volume air supply pipe delivcling to the minin chamber, a conveying tube leading latera ly out of the chamber of the'housing at one side of the same ha low the be per opening and plate and joining the v0 ume air supply pipe in front of the mixing chamber, a blast jet for a supply of carrying air entering the chamber of the-housing at the opposite side of the same in line with the said conveyin 'tube, and two sets of inclined blades locate with in the mixing chamber, the blades of the two spindle of the feed screw being extended through the'hopper opening into the chamber of the said housing, the hopper opening mounted upon the feed screw spindle to rotate therewith within the chamber of the said housing, the-face of the plate cob crating with the face of the inside wall of t e housing about the hopper opening to regulate the discharge of material through the said opening into the chamber of the housing, a jet burner, a tubular mixing chamber delivering to the burner, a vol ume air supply pipe delivering to the mixing chamber, a conveying tube leading laterally out ofthe chamber of the housing at one side of the same below the hopperopening and plate andjoiningthe volmue air supply pipe in front of the mixing'chamber, a blast get for a supply of carrying air entering the chamber of the housing at the opposite side of the same iu'lme with the said conveying tube, and a plurality of pairs of sets of sta a. plate larger than" emme tionary incliticd'blades located at intervals in the length of the mixing chamber, the blades of the two sets of each pair being oppositely inclined, the blades of one set of each pair being arranged in an annular series adjacent the wall of the mixing ch'amher, the blades of the other set of each pair being located within the space which is inclosed by the annular series of blades of the same pair and the blades of thc-corres mnding sets of adjacent pairs bein g oppositcl y inclined.

ii. In an apparatus of the kind described, in combination, a chambered housing bar-- lug two inlet and one outlet opening, a feed screw delivering to one oflhe inlet openings from without the chamber of the housing, lhe spindle of the feed sci-cwbeing extended through the said opening into the chamber of the housing, a plate larger than the last mentioned inlet opening of the housing mounted upon the feed screw spindle to mtate therewith within the chamber of the housing, the face of the plate coiiperating with the face of the inside wall of the housing about the said inlet opening to regulate the diswhargn oi. material through the said opening into the chamber oii'the housing, a jet burner, a conveying tube loading from the outlet opening of the housing to the burner and means for inducing a blast of air to enter the chamber of the housing through the other inlet opening and pass through the chamber of the housing and conveying tube to the burner.

lnan apparatus for burning powdered fuel, in combination, a combustion chamber, a burner housing having a contracted throat and a flaring mouth entering the combustion vrr-hamber, a pair of independent swinging plates mounted within the flaring mouth of 8. in an apparatus for burning powdered fuel, in combination, a combustion chamber, a burner housing having a contracted throat and a flaring mouth entering the combustion chamber, a pair of independent chambered swinging plates mounted within the flaring mouth of the burner housing, a pair of tubular trunnions for each of the said plates journaled in the walls of the burner housing at its said throat and extending through thesuid walls, the bores of the trunnious communicating with the chamber of the corrcspondii'ig' plate, water supply and discharge pipes connected to the two trunnions of each plate, and volume and carrying air supply pipes delivering to the-burner housing from without the combustion chamber.

9. lln an apparatus for burning powdered fuel, in combination, a burner, a tubular mixing chamber delivering to the burner, an air and fuel supply pi pe delivering to the said mixing chamber and two sets of inclined blades located within the mixing chamber, the blades of the two sets being oppositely inclined and the blades of one set being arranged in an annular series adjacent the wall of the mixing chamber and the blades of the other set being located within the space which is inclosed by the air and fuel current passing through the 15 mixing chamber, the said diiferent'parts of the air and fuel current bein located adjacent the axis 0 respectively the mixin chamber and adjacent the wall of said chamber.

AUBREY J. RINDLE. 

